Some may think the end is nigh for email — with services like Facebook coming to replace it as a one-stop communications hub for consumers — but going by the numbers out today from SendGrid, the email delivery company, thoughts like that may be a bit premature.

The company — which now works with 60,000 businesses, including buzzy brands like foursquare, Pinterest, Airbnb, Twilio, Spotify and Pandora to send out email communications to their users — says that it has now sent 45 billion emails since opening for business in 2009 — and use is accelerating. Twenty billion of those emails were sent in 2012 alone — a sign that no matter what innovations are coming to the web and mobile, many users (and companies) are still looking to email as a solid touchpoint.

Currently, SendGrid is working at a rate of sending 3 billion emails per month, and 90,000 per minute (my inbox and I are crying as we write this), covering such actions as signups, password changes, check-ins, notifications and follower requests.

To combat that, SendGrid is looking to scale itself up as fast as possible: in January it raised $21 million in its bid to outpace the others, with total funding around $27 million.

It has recently expanded its operations to offices in San Francisco, New York, Anaheim and Germany, in addition to its base in Boulder, Colorado. And it says employee headcount is up by 70 percent this year (100 employees total), with its customer base up by 50 percent, according to Robert Phillips, VP of marketing for the company.

Its business model rests on the fact that before SendGrid existed, tech companies had to build their own custom email systems from scratch, which was expensive, time consuming and difficult, notes Phillips. SendGrid’s cloud-based service offers and API that lets developers integrate the email directly into their services — costing a “fraction” of a custom build.

And the email portion of a site is more important than you might initially think. Social networking sites like Twitter and Pinterest have a big pull in their own rights because of the content draw and the fact that this content is constantly changing. But if you’re a user that has pulled away from going there regularly, an email can serve as a reminder of the service and your activity in it — I’ve noticed, for example, Twitter starting to send out a weekly update in the last couple of months that notes my new followers and other activity on the site. I’m a big fan of Twitter, so perhaps don’t need the updates, but those emails are great for another site that does the same thing, Pinterest, which I hardly ever visit, but may be more likely to as a result of their weekly updated emails.

SendGrid says that web applications are sending around 631,000 emails every month coming from user actions triggering email alerts — meaning not all of the email that is getting sent out there is being pushed by companies, but requested by the users, as well.